Most helpful positive review

I posted this about the Transcend 32 GB SDHC card that was getting trashed in reviews by Canon owners. It also applies to the Sony card (read down), and readers may find it helpful in evaluating SD cards in general.

The 1-star threads on the Transcend are like watching a committee of blind men describing an elephant. Unsurprisingly, no one has the complete picture, but a lot of Canon owners think these cards are bogus. SD card technology is very complex, the Class system is often misunderstood, and there is a long history of compromised cards appearing on eBay -- or even from reputable dealers who have been hoodwinked. Kingston cards are most often faked (or taken from the midnight production run); that's because Kingston has about a third of the flash card market and doesn't forge their own chips, but any manufacturer can be spoofed. It doesn't pay to buy cheap cards on eBay or less reputable sources.

An SD card contains a controller chip and flash memory chips, even the microSD versions. Realize that SD means Secure Digital, and that security comes from crypto managed by the controller (MMC cards didn't have that bloat, but Hollywood DRM requirements made sure they faded). The controller can be pretty powerful: the Samsung SD controller is a 32-bit ARM TDMI chip with 128 k of code space -- that's cell phone power. It handles I/O and fading (when the card slowly wears out its NAND sites after about 100,000 hits so writing is randomly distributed and kept track of), the factory self-test, and a host of other functions, but it can also be programmed to report a false storage capacity. Sometimes the firmware on the controller or its crypto or something else on certain cards leads to problems with certain hardware, as it has, for example, with the Samsung Galaxy III and maybe the Canon cameras. Usually the card is found to confirm to SDcard dot Org specifications and the hardware is to blame, but you never know.

To test the actual capacity of your card, use H2testw, which is free. It writes the full amount of data to the card and then reads it back (this nukes whatever was on the card). This can take more than an hour with a 32 GB card but it tells you if the card indeed holds 32 GB or if it has problems. H2testw also gives you read and write speed numbers, but it's unclear whether the numbers are for random read/write, or sequential read/write or a mix. Sequential write is what photographers and videographers most care about.

Sometimes a Class 6 card might appear to test faster than a Class 10 card, when using computer read/write tests or even in a camera that wasn't designed with higher capacity cards in mind. That's because such cards use smaller block sizes (there's no cache on an SD card). Explaining the significance of this is getting too far into the weeds for an Amazon review, and modern devices and their firmware should not have that limitation.

To test random and sequential read/write speed, use CrystalDiskMark, also free. Run the full suite; it won't take long. CrystalDiskMark requires that the card be formatted, and the most reliable way to do that is to use the free tool from sdcard dot org. A 32 GB card will may report 39.9 GB before formatting and 29.8 GB after; don't worry, you haven't been ripped off.

Unfortunately, there's no easy way to read the manufacturer's ID off the SD card, even in Linux, to determine who actually made the card, because you have to have the card connected directly to a motherboard; an SD-to-USB adapter won't work because it doesn't pass through disk data, and that's what's in nearly all computers. But what do you care, so long as the card's as big and fast as claimed?

Now, what about the Transcend 32 GB SDHC C10 card? Here are full test results from CrystalDiskMark:

So you can see that the sequential write speed, what matters to a photographer or videographer, is over 13 MB/s, more than 30% above the C10 spec. The other speeds aren't too shabby, either. There's no way that this card is too slow for a contemporary camera, still or video, that is functioning and designed properly.

Also on Amazon for a very attractive price is a Sony 32 MB SD card. Here are the full CrystalDiskMark test results for it:

So the Sony is slightly faster, 40% over spec, on its sequential write. H2testw also reported full capacity and no errors for this card, so they are both top notch (The Sony doesn't come with a little case and the case for the Transcend case is about twice as big as it needs to be and so won't fit in the little pockets in a modern camera bag. Big deals.)

Just for reference, here are the results for a contemporary USB thumb drive:

As you can see, this USB drive is faster than the SD cards for reading, such as for playing music, running software, or looking up data, which shows that it is nicely optimized for its intended functions.

As an aside, anyone who thinks they have lost data on an SD card can recover pictures using the free tool at z-a-recovery or recover everything(!) with the free PhotoRec tools.

So, if people want to whine about these SD cards in their particular cameras, they should run these simple, free tests and reach their own conclusions about whether the cards are "too slow." The cards test above spec objectively. And they both work flawlessly on my still (not Canon) and video cameras. I think they have gotten a bad rap on Amazon from people who don't have the full picture, so to speak.

I've also posted this as a review on the Transcend 32 GB page. I hope you found it informative.

Most helpful critical review

My card failed just past Amazon's 30-day warranty. I then spent more than 90 minutes talking to 6 different Sony reps in 6 different departments (and probably 6 different countries), trying to get a replacement card. Most reps didn't know what I was talking about, and all gave useless advice, and argued with me about the warranty. (One said that devices sold by Amazon may be counterfeit, so the warranty is only 90 days. I doubt this is true, but why argue with me about it, when the card is only 44 days old?) I was cut off twice, and had to repeat my info more times than I can count. Absolutely atrocious customer service. So, if you get a good card, great. If you get a bad card, you're SOL.

Update after 2 weeks of playing with Sony: I have now spent at least 3 hours on the phone with more than a dozen different reps, plus several emails, and they all keep passing the buck. I finally got a direct phone number for the Sony Media Storage department (877-440-3453), but when you call that number -- and I've tried every day for the past 10 days -- you get a message saying they're not available now, please leave a message -- but you can't leave a message, because "the user's mailbox is full." Unbelievable. Normally I wouldn't go to this much effort for a $20 product, but now it's a matter of principle. Sony makes some cool stuff, and I've bought a *lot* of it over the past 40 years -- but never again.

There was a problem filtering reviews right now. Please try again later.

I posted this about the Transcend 32 GB SDHC card that was getting trashed in reviews by Canon owners. It also applies to the Sony card (read down), and readers may find it helpful in evaluating SD cards in general.

The 1-star threads on the Transcend are like watching a committee of blind men describing an elephant. Unsurprisingly, no one has the complete picture, but a lot of Canon owners think these cards are bogus. SD card technology is very complex, the Class system is often misunderstood, and there is a long history of compromised cards appearing on eBay -- or even from reputable dealers who have been hoodwinked. Kingston cards are most often faked (or taken from the midnight production run); that's because Kingston has about a third of the flash card market and doesn't forge their own chips, but any manufacturer can be spoofed. It doesn't pay to buy cheap cards on eBay or less reputable sources.

An SD card contains a controller chip and flash memory chips, even the microSD versions. Realize that SD means Secure Digital, and that security comes from crypto managed by the controller (MMC cards didn't have that bloat, but Hollywood DRM requirements made sure they faded). The controller can be pretty powerful: the Samsung SD controller is a 32-bit ARM TDMI chip with 128 k of code space -- that's cell phone power. It handles I/O and fading (when the card slowly wears out its NAND sites after about 100,000 hits so writing is randomly distributed and kept track of), the factory self-test, and a host of other functions, but it can also be programmed to report a false storage capacity. Sometimes the firmware on the controller or its crypto or something else on certain cards leads to problems with certain hardware, as it has, for example, with the Samsung Galaxy III and maybe the Canon cameras. Usually the card is found to confirm to SDcard dot Org specifications and the hardware is to blame, but you never know.

To test the actual capacity of your card, use H2testw, which is free. It writes the full amount of data to the card and then reads it back (this nukes whatever was on the card). This can take more than an hour with a 32 GB card but it tells you if the card indeed holds 32 GB or if it has problems. H2testw also gives you read and write speed numbers, but it's unclear whether the numbers are for random read/write, or sequential read/write or a mix. Sequential write is what photographers and videographers most care about.

Sometimes a Class 6 card might appear to test faster than a Class 10 card, when using computer read/write tests or even in a camera that wasn't designed with higher capacity cards in mind. That's because such cards use smaller block sizes (there's no cache on an SD card). Explaining the significance of this is getting too far into the weeds for an Amazon review, and modern devices and their firmware should not have that limitation.

To test random and sequential read/write speed, use CrystalDiskMark, also free. Run the full suite; it won't take long. CrystalDiskMark requires that the card be formatted, and the most reliable way to do that is to use the free tool from sdcard dot org. A 32 GB card will may report 39.9 GB before formatting and 29.8 GB after; don't worry, you haven't been ripped off.

Unfortunately, there's no easy way to read the manufacturer's ID off the SD card, even in Linux, to determine who actually made the card, because you have to have the card connected directly to a motherboard; an SD-to-USB adapter won't work because it doesn't pass through disk data, and that's what's in nearly all computers. But what do you care, so long as the card's as big and fast as claimed?

Now, what about the Transcend 32 GB SDHC C10 card? Here are full test results from CrystalDiskMark:

So you can see that the sequential write speed, what matters to a photographer or videographer, is over 13 MB/s, more than 30% above the C10 spec. The other speeds aren't too shabby, either. There's no way that this card is too slow for a contemporary camera, still or video, that is functioning and designed properly.

Also on Amazon for a very attractive price is a Sony 32 MB SD card. Here are the full CrystalDiskMark test results for it:

So the Sony is slightly faster, 40% over spec, on its sequential write. H2testw also reported full capacity and no errors for this card, so they are both top notch (The Sony doesn't come with a little case and the case for the Transcend case is about twice as big as it needs to be and so won't fit in the little pockets in a modern camera bag. Big deals.)

Just for reference, here are the results for a contemporary USB thumb drive:

As you can see, this USB drive is faster than the SD cards for reading, such as for playing music, running software, or looking up data, which shows that it is nicely optimized for its intended functions.

As an aside, anyone who thinks they have lost data on an SD card can recover pictures using the free tool at z-a-recovery or recover everything(!) with the free PhotoRec tools.

So, if people want to whine about these SD cards in their particular cameras, they should run these simple, free tests and reach their own conclusions about whether the cards are "too slow." The cards test above spec objectively. And they both work flawlessly on my still (not Canon) and video cameras. I think they have gotten a bad rap on Amazon from people who don't have the full picture, so to speak.

I've also posted this as a review on the Transcend 32 GB page. I hope you found it informative.

There was a problem loading comments right now. Please try again later.

As of the end of May 2013, the Sony 32 GB SDHC R40 is on sale for under $20, so the card is a bargain in light of its reasonable performance specifications. Note however that to maximize the performance of this card, your host device must be UHS-1 compatible, which means many older devices will find this card to be a poor performer. In newer devices, this is a good card-reasonably fast, waterproof, and with recovery software (if needed) available for download.

After receiving this card, I tested it against a bunch of other SD cards in my personal inventory. Note that there is some room for error (due to hand/stopwatch reaction time). Nevertheless, it's a good relative overview. I tested using a UHS-1 capable reader and files of known size. Here's a summary of the results:

And just for fun--here's what a number looks like for an older compact flash with UDMA controller:

Sandisk Extreme IV 4 GB compact flashREAD: Not testedWRITE: 33 MB/sec

So, as you can see, while this Sony card is not the fastest performing card out there, it's performance is still quite good in the latest gear. Also, a quick word about video and transfer rates. Digital video is recorded in "megaBITS" per second, while these cards are speed rated in "megaBYTES" per second. That makes it a bit confusing. At the moment, digital SLRs from the factory are at about 24 up to 100 megabits/second in terms of their video rate. To convert bits to bytes, divide by 8...so that becomes 3 MB/sec to 12.5 MB/second. For most digital SLRs out there, even the Sandisk Ultra is fast enough for video, but if your camera has a high bitrate option, this Sony has enough headroom for sustained file writing. The Sandisks are still king of the mountain, but they do cost more. Sandisk has long underrated their higher end cards; even older Sandisks are often faster than newer cards from other makers (like the older compact flash example above). If you absolutely need the higher performance, go with the Sandisk Extreme or Extreme Pro, but you'll pay for it. From my own numbers, I'm comfortable with the Sony for day to day use for my D800. If I really need speed though, I'm going with compact flash over SDHC.

This Sony SDHC card is a pretty nice memory card. Although it is labeled to read up to 40 Mb/sec, I found that I actually got better speeds when reading from the card. I consistently got up to 64Mb/sec read speed...which is blazingly fast. Considering that Class 10 SDHC cards only have to meet 10 Mb/sec minimum requirements, this card went well above and beyond. I bought this card to use with my new Canon T3i DSLR camera, so this speed is coming in handy. In fact, if you are buying a card to use with a high resolution digital camera or hd camcorder... I wouldn't recommend getting a card that is slower than a Class 10 card. With that being said, I would highly recommend this card for such purposes. It has one of the fastest 'read' speeds I have come across in an SD card. I haven't yet tested the 'write speed' yet but I will post the results once I do.Now, although this card works very well... it isn't the most affordable card I've come across. I've had very good luck with the brand 'Transcend' and their memory cards. I'd recommend you go check some of those reviews before you choose the card that works best for you. I have some reviews posted here at Amazon for Transcend brand SD, Micro-SDHC, and SDHC cards.

Also, Did you know? :If you have many electronics that use Micro-SD cards (for example, perhaps your mobile phone), you should consider buying a Micro-SD card with a full-sized SDHC adapter. This will allow the Micro-SD card to be used in SDHC or SD devices as well. All you do is slide the micro-SD card into those full sized SDHC card adapters and put it in a compatible SDHC device and it will work. This versatility allows you to use that Micro-SD card in many devices instead of ust Micro-SD devices. There are also Mini-SD adapters that allow the Micro-SD card to be used in Mini-SD card devices too. Also, any brand Micro to SDHC adapter or Micro to Mini-SD adapter will work with your card, even if it doesn't match the brand of your Micro-SD card. For example, you could buy a Transcend or Kingston brand Micro-SD card and use a Sandisk branded SDHC card adapter. That's because they all use and meet the same SD card standard that was set to ensure compatibility.

The last thing you should keep in mind while considering buying memory cards is that if you are buying an SD card for an older device (5 or more years old), make sure that it is compatible with the newer SDHC standard. New SDHC cards are not backwards compatible with older devices that were made to use only SD standard cards. If your device is not compatible with SDHC, you must make sure to buy a regular SD compatible card. However, if you have a new device that IS compatible with SDHC cards, your device is also compatible with older SD standard cards. For more details, see notes below.

IMPORTANT SPECIAL NOTES ABOUT SDHC MEMORY CARDS:

-SDHC cards are not compatible with most older SD cameras, SD devices, or SD card readers.

-SDHC cards are rated by speed using different "classes". There are currently 4 data transfer speed classes available for SDHC cards. These classes are "class 2, class 4, and class 6, and the new class 10. For example, "Class 2" would have the slowest read/write speed while "Class 10" currently has the fastest read/write speed. So if you have a device in which speed may play a crucial role, make sure you buy a higher "class" SDHC card. Please note that this SDHC card no longer has the fastest read/write speed available. There is now a new class, called "Class 10". Class 6 has a minimum read/write speed of 6MB/sec... while Class 2 has minimum speed rating of 2MB/sec, and Class 4 is 4MB/sec. Starting to see the pattern?

-SDHC cards are not only for digital cameras. Any device that is compatible with SDHC cards should work with this card. Just make sure that it takes a full-sized SDHC card. For example, there are some devices that use smaller cards... like Micro-SDHC or Mini-SDHC. If you have a Micro-SDHC or Mini-SDHC card already and want to use it in a full sized SDHC device, you can buy an adapter that can make those cards larger so that they can fit into a full sized SDHC card slot. However, you cannot make a full size SDHC card fit into a Micro-SDHC or Mini-SDHC slot.

SO WHAT'S THE DIFFERENCE BETWEEN "SD CARDS" AND "SDHC CARDS?

SDHC is basically an upgrade to the older SD cards. The reason they upgraded it was to achieve greater data transfer speeds AND capacity than previously possible with normal SD cards... and to do this, they had to redesign the card (which is why it's not compatible with normal SD devices). This was necessary because digital cameras and digital video cameras these days have higher resolutions, which equate to larger file sizes and faster data transfer needs.

Now that many digital cameras also can record HD video, you may consider getting a larger capacity card because video takes much more space than photos. The size of the video varies from camera to camera depending on what resolution and video compression the camera uses. If you plan on taking lots of video (especially HD video), I would consider getting at least a 16GB card. Check your camera specifications to see how many minutes per Gig of memory your camera can capture ...to gauge how big of a memory card you'll want to get to meet your needs.

Special Note on regular SD Cards:If you primarily take casual photos and don't need a exceptionally fast read/write capable card, you should know that newer cameras that take "SDHC" cards will also work with older normal "SD" cards. These older cards are cheaper than the new SDHC cards, so this may be something to consider. So to sum things up, newer cameras will take SDHC and regular SD cards, but older cameras that use SD cards may not be able to use SDHC cards. This is because newer technology is usually made to be compatible with older technology (the technical term used to describe this is "backwards compatibility") ... but older technology may not have the hardware necessary to run newer tech (technical term used is "obsolete"... just kidding! ;)

There was a problem loading comments right now. Please try again later.

My card failed just past Amazon's 30-day warranty. I then spent more than 90 minutes talking to 6 different Sony reps in 6 different departments (and probably 6 different countries), trying to get a replacement card. Most reps didn't know what I was talking about, and all gave useless advice, and argued with me about the warranty. (One said that devices sold by Amazon may be counterfeit, so the warranty is only 90 days. I doubt this is true, but why argue with me about it, when the card is only 44 days old?) I was cut off twice, and had to repeat my info more times than I can count. Absolutely atrocious customer service. So, if you get a good card, great. If you get a bad card, you're SOL.

Update after 2 weeks of playing with Sony: I have now spent at least 3 hours on the phone with more than a dozen different reps, plus several emails, and they all keep passing the buck. I finally got a direct phone number for the Sony Media Storage department (877-440-3453), but when you call that number -- and I've tried every day for the past 10 days -- you get a message saying they're not available now, please leave a message -- but you can't leave a message, because "the user's mailbox is full." Unbelievable. Normally I wouldn't go to this much effort for a $20 product, but now it's a matter of principle. Sony makes some cool stuff, and I've bought a *lot* of it over the past 40 years -- but never again.

There was a problem loading comments right now. Please try again later.

I purchased 2 of these cards, and each one has outperformed what I thought was a better brand (not mentioning any names, but it rhymes with fandisk lol)

Though all cards are rated at Class 10, UHS-1, their performance is wildly different. This card I can consistently read dead on 72MB/s. With the sandisk, it's very inconsistent and around 40MB/s. Write speeds are way more important than read speeds though, as you all know. I had a real problem with my T3i sporratically prematurely stopping recording. It didn't do it all the time, so that made the issue more irritating and difficult to troubleshoot.

I then ran a series of tests, which confirmed with the sandisk, I was getting anywhere from 11-14MB/s write speed. extremely inconsistent. Each sample I got of this card pegs just over 20MB/s write speed, every time. Almost NO variation.

I'm blown away, every part of my DNA hates Sony products (can you say magic gate?). Yet, I get this card out of necessity, and it turns out to be a very legit upgrade in performance from a card I thought would easily beat it. We're talking 20-30% margins here, that's big when dealing with recording live HD video.

Edit: What's with all of these pics of people screenshotting card performance measured from a USB 2.0 reader? That only tells us how crappy the reader is, if anything. I've included a screenshot confirming the speeds I've claimed in this article using my USB 3.0 card reader.

There was a problem loading comments right now. Please try again later.

Bought this 6 months ago. It's been in my Chromebook for 6 months. One day just wasn't recognized. I tried to get it to be recognized by several different devices with no luck. Can't even reformat as it isn't recognized by any device. Called Sony as was on the phone with them for 2 hours only for them to tell me that they don't offer ANY warranty on SD cards as they are accessories. When I asked if that meant that a week after I bought it that I would be out of luck if it stopped working, the answer was "Yes". THEN, the Sony rep started to say that Amazon carries products that SAY that they are Sony products but are not. I asked the tech support person why my model number and serial number made it through their Rescue Program Screener and he dodged the question. Bottom line, Sony has their name on an inferior product and knows it. Shame, Sony was once the gold standard of electronics and is now reluctant to stand by its product. On top of that, they are blatantly stating that Amazon sells fraudulent Sony products. I think Amazon may want to dig into that a bit further.

There was a problem loading comments right now. Please try again later.

Bought this to replace the SD card that comes with the 3DS XL. The class definitely makes a difference with load times. Seems to be about 2-3 times faster loading and saving in Animal Crossing.

My advice, if you're going to buy a bigger capacity card for your 3DS, go with a class 10 card. If you search around a bit they're not any more expensive than the abundance of class 4 cards out there, and the performance boost is well worth it. This card works great and I got it for the same price as a 32GB class 4 Sandisk card.

There was a problem loading comments right now. Please try again later.

I am using this card of a Canon EOS Rebel T3i. For pictures this card work just fine. However,do not handle HD videos. Your camera will stop after 5 second and you will received the error message "recording stopped automatically".

There was a problem loading comments right now. Please try again later.

Well, this was purchased for new Pentax K-30 and a K-01 cameras.Both cameras gave the same startup error and couldn't read the memory card. The card works in all my other devices, and even in a 3 year old Pentax K-x.So, it's incompatible with new Pentax cameras.Nothing I tried made it work for my new Pentax. Formatting via computer or K-x. Full format (not necessary for flash memory)and even after updating camera firmware - nada!It may be SONY or Pentax fault. Whatever, it was irritating to have to put it in something other than what I bought it for.